This invention relates generally to electrical components used in a meter box containing an electrical meter, and more particularly to a socket assembly and related features used in a such an assembly.
In conventional meter boxes, an electric meter is plugged into a socket assembly mounted in the box. In a single-phase, 3-wire power system, for example, the socket assembly typically includes two power line connectors for connecting the power supply lines to the socket assembly, two power line connectors for connecting the power load lines to the socket assembly, and a meter bypass system. During normal operation, electrical current flows from the power supply lines, through the meter, to the power load lines. During meter repair or replacement, the bypass system is used to route the current along a path bypassing the meter so that the meter can be removed for repair or replacement without interrupting power to the installation (e.g., residence) being serviced.
In one type of conventional bypass system a slide connector is mounted for sliding movement along a linear line of action between a meter-bypass position in which the slide connector is in electrical contact with a first power line connector connected to the power supply line and a second power line connector connected to the power load line, and a non-bypass position in which the slide connector is out of electrical contact with one of the two power line connectors. Each power line connector comprises a metal jaw support, a jaw pivotally mounted on the jaw support, and a spring to bias rotation of the jaw. Notably, the jaw support is constructed of two separate metal pieces joined together at joints by being swaged, riveted or brazed together in an assembly process. The upper ends of the jaw supports and the opposing upper ends of the jaws define a pair of sockets for receiving the plugs of an electric meter. When the bypass system is its non-bypass (meter conducting) mode, current flows from the power supply line to the power load line along a path which includes the meter and the two-piece metal jaw supports of the power line connectors. Accordingly, current must flow through the joints in the metal jaw supports.
Running current through the joints in the jaw supports has several disadvantages. First, the conductivity through the joints is generally less than what the conductivity would be through a one-piece jaw support. Second, the joints may not be properly formed due to errors in the assembly process, thereby further reducing the conductivity of the jaw support. The reduced conductivity can cause heat buildup which can lead to eventual failure of the product.
Moreover, the joints in the jaw supports adversely affect the structural strength of the socket assembly. The socket assembly has to be strong enough to withstand the forces involved in moving a slide connector between its non-bypass position and its bypass position. Because actuation of the slide connector involves forcibly wedging cam-shaped ends of the slide connector into contact with respective jaw supports, thereby causing the jaws of the supports to rotate against the resilient bias of the springs, the socket assembly has to be able to withstand considerable lateral forces. The reduced structural strength resulting from multiple joints, especially in combination with potential weakening of the material strength caused by excessive heat buildup, can contribute to premature failure of the system.
U.S. Pat. No. 5,775,942 issued Jul. 7, 1998 to Jeffcoat discloses a jaw support made out of one piece of metal. However, the jaw support is designed to operate in a different type of bypass system, i.e., one where a lever arm rotates a knife blade connector into contact with the jaw supports. The rotating connector design shown in the Jeffcoat system cannot be used in a bypass system which uses a linear-slide connector because of the different configurations involved. Further, the connector subassemblies in the Jeffcoat System are designed to have structural strength in a direction to accommodate a rotating connector, not a linear-slide connector.
Also, in prior socket assemblies using conventional power line connectors, substantially all electrical current passes through the jaw supports when the meter is plugged into the socket assembly and the bypass system is in its non-bypass mode. This can result in overheating of the jaw supports and possible premature failure.
There is a need, therefore, for an improved socket assembly which avoids one or more of the aforementioned problems.